Nibi Metrics
Real-time water levels, forecasts, and alerts for lakes and rivers across Canada and the US. Built on official government data.
Nibi Metrics turns raw gauge readings from official hydrometric networks into something a person standing on a dock can actually use: is the water high or low for today, which way is it moving, and how unusual is this? This page explains where every number on the platform comes from and what we do to it along the way.
Water Stories
For five years, spring 2019 was the mark every Lake Muskoka decision answered to. In April 2026 the lake went two centimeters higher - and the official books have not caught up yet.
Inside the freshet cycle that puts Manitoba shorelines at risk each year - and why 2026 broke the script.
The science of snow water equivalent and why it drives the season ahead.
What the numbers on the measuring stick actually tell you.
Why Central and South Texas rivers go from gravel beds to fifty-year records in an afternoon - including July 2026 on the Nueces.
One percent, every year, forever - unwrapping hydrology's most misunderstood phrase, and how it differs from our own percentiles.
Mary Lake Water Level
Live lake level, flow, historical records and forecast for Mary Lake in Muskoka, ON, Canada, built from official government gauge data.
- Location Muskoka, ON, Canada
- Watershed muskoka
- Primary gauge 02EB021 (Water Survey of Canada)
About Mary Lake
Mary Lake - A cherished waterway in Muskoka.
Nestled in the vibrant region of Muskoka, Mary Lake serves as a focal point for both relaxation and recreation. A beloved destination for cottagers and anglers alike, it harmonizes with nature while providing ample opportunities for boating and fishing activities. This prominent lake connects with several notable peers, including Big East River, Fairy Lake, and Lake Muskoka, anchoring it firmly in the heart of Muskoka's rich tapestry of waterways.
The watershed context
Mary Lake is situated within a drainage area of approximately 1,410 square kilometers, which contributes to the water levels and overall health of the lake. The Muskoka watershed, characterized by its network of lakes and rivers, plays a critical role in regulating water flow and quality in the area. As seasonal changes occur, Mary Lake experiences snowmelt-driven hydrology, with a spring freshet typically arriving from late April through May. This seasonal rhythm enriches the lake's ecosystem, encouraging vibrant aquatic life and providing essential resources for the surrounding habitats.
Why the data matters here
As of today, water levels at Mary Lake are being closely monitored, providing essential information for local stakeholders. Comparing the current reading against the median for this calendar day—as documented by the Water Survey of Canada—offers insights into the lake's health and water management strategies. This approach reveals deeper patterns in water levels, enabling residents and visitors to understand the ongoing fluctuations within this seasonal hydrology. Analyzing the data collected over 22 years strengthens our appreciation for how Mary Lake fits into the larger Muskoka region, ensuring that it remains a vital resource for generations to come.
How this page is built
Readings come from official government gauges and are rolled into daily records: the daily mean, high and low for every day on record. Each calendar day gets its own baseline from the full history, so the level you see is compared against what this specific date usually looks like rather than an annual average.
How Nibi Metrics works · Water stories
